But a new study suggests that switching to the Mediterranean diet can have a prolonging effect even if you don't start until you're over 65 years old.

The Mediterranean diet prioritizes plant-based meals, with dishes that are full of leafy vegetables, fruits, legumes, simple unrefined grains, olive oil, and primarily fish, chicken or other lean meats as protein. A team of researchers who studied a group of older adults in the Molise region of Italy found the Mediterranean diet was associated with a 25 percent overall decreased risk of death. Their findings were published in the British Journal of Nutrition earlier this month.

While the study didn't singularly identify a reason for why the Mediterranean diet prolongs life, Marialaura Bonaccio, an author behind the study and an epidemiologist at the Mediterranean Neuromed Institute, said all the diet's elements work together to aid your body's overall longevity.

Bonaccio and other researchers closely studied the health and diets of more than 5,000 people,65 or older, living in the region. These seniors were first selected for the study between 2005 and 2010, and researchers studied their food intakes until the end of 2015 using food questionnaires, eventually grading their intake by looking for heavy fruits, nuts, vegetables, legumes, fish, and moderate alcohol consumption.

Using a 0-9 scale, the study gave each participant a "Mediterranean Diet Score" based on how closely their diet matched a Mediterranean diet. The study found that risk of death became lower as each individual's score increased. Seniors who adopted the diet entirely—or those with a 7-9 score—enjoyed a 25 percent lower risk of death compared to those who scored between 0 and 3 points, after accounting for factors like age, sex, weight, physical fitness, and socioeconomic status.

Researchers found that even a semi-adherence to the diet—upping the amount of vegetables and legumes in your diet, for instance, or switching to olive oil—could help prolong your life. Each point earned by participants in the study was linked to approximately 6 percent lower risk of death overall.

“If you start a good healthy lifestyle when you are young, probably your benefit will be even greater,” Bonaccio told The Guardian. “But even if you are old and you start having a healthy lifestyle including diet you can benefit as well.”

The bottom line: It's clear that it's never too late to start improving your health by considering what you eat in your own kitchen.